Electrical insulating composition and process for manufacturing the same.



I vented a new and useful UNITED STATES PATENT OFFICE.

ANQNYME MATTHEY & RATION OF SWITZERLAND.

ELECTRICAL INSULATING COMPOSITION AND Specification of Letters Patent.

GO., OF VALLORBE, SWITZERLAND, A CORPO- P ROOESS FOR MANUFACTURlNG THESAME.

Patented Oct. 1c. 1906.

Application filed ii 21,1905. Serial No. 256,766.

To all whom it may concern:

Be it known that 1, CHARLES CLEMENT, chemist, of Vallorbe, Switzerland,have in- 9 Electrical Insulat-' ing Composition and a Process forManufacturin the Same, of which the following is aspeci cation. I Thepresent invention relates to a novel electrical insulatin compositionand the process for manu acturing the same, and es ecially refers to themanufacture of electrical and electrochemical a paratus.

The insulating compositlon accordin my invention possesses theadvantages 0' ing of great solidity, insulating power, very low cost.and fireproof to beof a very high electric and of being produced at aFurthermore, it is water-tight and may be heated up to 400 'centigradew1thout deterioration.

Heretofore electrical insulatin compositions have generally consistedo'wood or celluloid impregnated with parafiin or the like; but suchcompositions are very inflammable and liable to distort even at a lowheat. The'insulators manufactured out of sulfate of lime and amianthuseasily'break and are not impervious to water,but', on thecontrary, theyabsorb water through their pores,w 'ch causes their rapid deterioration,as does also extreme changes of temperature, which is not the case whenthe product resultin from the mixture of amianthus, sulfate o lime, andwater is impregnated with pitch.

In carry'in' out my invention I employ a composition firmed by a mixtureof amianthus, sulfate of lime, andwater, which is then molded to thedesired shape or may be spread into plates or sheets of differentthicknesses, after which it is allowed to dry and harden. Thecomposition in form is then put into a hot mixture of pitch or othercoaltar derivative to which some sulfur is added. Afterbein thoroughlyimpregnated it is taken out and allowed to cool. In the carrying out ofthis rocess the sulfur acts to vulcanize the pitc and it is graduallyvo1atil ized by the vulcanizing operation and chemical action and thecharacter of the material impregnated is thus changed, therebyincreasing itsinsulating and heat-resisting qualities. The resultingproduct is of great strength and durability and may be employed for avariety of purposes Where an effective and cheap insulating compositionis desired.

The essential feature of the new process is that it is to be carried outin two separate operations, in the interval of which the product isallowed to dry and harden. For obtaining the said product it isadvantageous to mix ten per cent. of amianthus and ninety per cent. ofsulfate'of lime with just thenecessary amount of water to geta plasticmass, which may be molded in variousforms or spread into plates. Thematerial thus obtained is impregnated with pitch and sulfur in a bath ofsuch materials.

I claim as my invention- 1.. An insulating composition consisting ofamianthus, sulfate of lime, water, pitch and sulfur.

2. The hereindescribed process for making an insulating com ositionconsisting in mixing amianthus, sul ate of lime and water to a suitablepaste, drying the same and then subjecting the product so obtained toimpregnation in a bath of pitch and sulfur.

3. The herein-describedprocess for making an insulating compositionconsisting in mixing ten per cent. of amianthusand ninety per cent. ofsulfate of lime withwater to make a suitable paste, drying and moldingthe same and then subjecting the product so obtained to impregnation ina bath of pitch and sulfur.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES CLEMENT.

Witnesses G. MERPHRIEM,

" G. GROBET.

